Yokozuna Musashimaru had little trouble toppling rank-and-filer Akinoshima to remain undefeated Monday but Musoyama, Tochiazuma and Kaio all fell on a day of bad luck and shoddy sumo for ozeki at the Summer Grand Sumo Tournament.

Ozeki Chiyotaikai manhandled Mongolian Kyokutenho (3-6) to remain undefeated in a key bout at Tokyo's Ryogoku Kokugikan but Kyokushuzan, who had been the unlikely co-leader, was also tripped up for his first loss in the 15-day meet.

In the day's final bout, grand champion Musashimaru (9-0) was not fazed in the least as Akinoshima (3-6) tried to reach in for his sash to yank him forward and otherwise throw off his balance.

But the burly yokozuna slid his right hand under the armpit of the No. 5 maegashira for a wedge and calmly shoved him to the edge where he slammed the Futagoyama wrestler down hard.

Musashimaru now shares the lead with ozeki Chiyotaikai as the only wrestlers with spotless records.

Musoyama had the toughest break of the losing ozeki trio after judges ruled that the Musashigawa stable ozeki stepped out with his right foot before blasting Mongolian Asashoryu into the ring seats. Both wrestlers stand at 6-3.

Meanwhile, Tochiazuma was caught sleeping after third-ranked Takanowaka (3-6) upset his balance with some fierce slaps to the head and saddled the ozeki with his third loss.

Komusubi Wakanosato (5-4) wrapped up Kaio in a matter of seconds and shoved him hard on the ring's edge to hand the ozeki his fourth loss.

Kyokushuzan (8-1) fell to Tosanoumi (5-4), who sent the 10th-ranked wrestler flying out in a salvo of slaps.